1. Field
This disclosure relates generally to varactor circuits, and more specifically, to varactor circuits for a voltage controlled oscillator.
2. Related Art
Voltage controlled oscillators (VCOs) are increasingly required to provide a wide range of frequencies. Such VCOs are also required to operate with a high degree of accuracy despite process, voltage, and temperature variations. These constraints can be difficult to satisfy in VCOs that are used at extremely high frequencies (e.g., in the range of frequencies from 30 to 300 gigahertz). This high range of frequencies corresponds to a wavelength of one to ten millimeters, which is also referred to as the millimeter wave (mmW) band. The capacitance provided preferably takes up little space and also the circuits for implementing the use of the capacitance should also not take up too much space.
Accordingly, there is a need for capacitor circuits for a voltage controlled oscillator that improve upon one or more of the issues raised above.